EPA Actions on Induced Seismicity Philip Dellinger, Chief Ground - - PowerPoint PPT Presentation

EPA Actions on Induced Seismicity

Philip Dellinger, Chief Ground Water/UIC Section US EPA Region 6 Dallas, Texas

Disclaimer

These slides and the information contained in them have been prepared by EPA staff for informational purposes only. They should not be relied on for regulatory compliance purposes and do not necessarily reflect EPA’s official policy and legal positions. To the extent any information in these slides is inconsistent with the statutes and regulations identified herein, the statutes and regulations control.

Induced Seismicity Presentation

• EPA’s Authority
• Our History of Involvement
• EPA National Technical Workgroup
• Summary Points

EPA’s Authority

Safe Drinking Water Act

• Authorizes the Federal Underground

Injection Control (UIC) program

• Requires protection of Underground Sources
• f Drinking Water
• Requires development of UIC regulations
• Establishes options for state UIC program

delegation

UIC Injection Well Classes

I. Industrial or municipal deep wells

• Non-hazardous & hazardous

II. Oil and gas related deep wells III. In-situ mining wells

• IV. Shallow hazardous waste wells (banned)

V. Wells not included in Classes I-IV

• Geothermal, experimental, and other wells
• VI. Geosequestration wells

UIC Seismicity Related Regulations

• Siting & testing requirements
• Class I Hazardous
• Class VI Geosequestration
• All classes: Director discretion
• Class V Geothermal – no specific rules
• DOE guidelines in-progress

EPA’s History of Involvement

EPA Involvement – Induced Seismicity

• 1990 USGS report in cooperation with EPA
• Tracking seismicity events & State responses
• North Texas & Arkansas
• Response to citizen complaints
• EPA/ORD National Hydraulic Fracturing (HF)

Study excludes seismicity

• HF generally yields microseismicity; -2 to +1 mag.
• Established project under national workgroup

EPA National Technical Workgroup

EPA Induced Seismicity Workgroup

• Task: Develop technical options to assist

regulators in managing seismic risks

• Timeframe: June to December 2011
• Region 6 assigned lead
• Workgroup representatives from EPA HQ, various

EPA Regional offices and State agencies

EPA Induced Seismicity Workgroup

• Final product by end of 2011
• Limited to Class II disposal wells
• Established six part strategy

Seismicity Workgroup Strategy

1) Literature review 2) Three case studies

• North Texas; Central Arkansas; & Braxton Co.,

West Virginia

• Engage researchers
• Request specific information from operators

Seismicity Workgroup Strategy

3) Explore reservoir engineering approaches

• Industry & regulatory experience
• Pressure transient test analysis
• Operational injection data evaluation

Log-Log Plot of a Disposal Well Exhibiting Radial Flow

Transition period Unit slope during wellbore storage period Derivative flattens during radial flow period

Falloff Test from Suspect DFW Area Disposal Well

Half slope trend on pressure and derivative representative of linear flow due to a fracture Flat linear derivative indicating linear flow Derivative decline indicating pressure support

Seismicity Workgroup Strategy

4) Partner with USGS seismologists 5) Develop decision tree

• Practical application
• Investigate potential regulatory tools
• Provide rational approach with options

6) Solicit peer review

UIC Seismicity Summary

• Existing UIC authority to address risks
• EPA developing a strategy with options for

UIC programs to manage seismic risks

• Risk assessment of seismic events
• Based on actual injection details
• Coupled with geologic interpretation
• Product based on existing knowledge level

Induced Seismicity Summary Points

Arkansas Moratorium area

Questions?